The present invention relates to a gas supply coupling for delivering natural gas to a combustion chamber of a water heater and, in particular, to an inexpensive coupling incorporating a shield which facilitates connection between a gas supply line and a gas supply tube.
Domestic water heaters use either electricity or a combustible fuel to heat a supply of water for use on demand by the homeowner. The fuel may include propane or natural gas which are delivered to a combustion chamber proximate the water tank. The fuel is combusted within the combustion chamber to heat and maintain the water at a predetermined temperature. In order to service and deliver fuel to the combustion element, the combustion chamber is typically open to the exterior of the water heater. This may create a path for other gases to reach the combustion element.
Water heater combustion chambers eliminate exterior combustion by utilizing a functionally sealed combustion chamber which controls the gas flow exteriorly of the chamber. The sealed chamber, however, may complicate manufacture and assembly of the water heater. A sealed chamber reduces many of the assembly tolerances between the control unit/regulator and the burner. In addition, the gas supply must pass through a sealed door for delivery of the combustion fuel. One such sealed door includes a flare connection and threaded nut fitting between a gas supply line which extends outside of the combustion chamber and a gas supply tube on the interior. Although effective, the connection components are rather expensive which further increases the per unit water heater manufacturing expense.
Accordingly, it is desirable to provide an uncomplicated and inexpensive connection through a water heater sealed door.